$ git clone -n https://src.fedoraproject.org/rpms/rust-bcder.git /var/lib/mock/f45-build-40451-772/root/chroot_tmpdir/scmroot/rust-bcder
Cloning into '/var/lib/mock/f45-build-40451-772/root/chroot_tmpdir/scmroot/rust-bcder'...
$ git fetch origin 9c67db78a6c46e4b84c77ec3dba79ee0afb95a9c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-bcder
 * [new ref]         9c67db78a6c46e4b84c77ec3dba79ee0afb95a9c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9c67db7 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild